Angiogenesis, the formation of new blood vessels, has been intensively studied over the past several decades because of its fundamental importance in tissue development, vascular diseases, and cancer. Angiogenesis is most active during fetal development. After birth angiogenesis is an important physiological function in the ovary, placenta, and in wound healing.
Pathological angiogenesis, that is inappropriate and unregulated, is a prominent feature of malignancy that facilitates tumor growth and metastasis. Improved treatments of malignancies that have progressed to the proangiogenic phenotype require relevant models to test the safety and efficacy of innovative antiangiogenic therapies.
There are a number of methods available for identifying potential antiangiogenic agents. One of these involves examining the effects of an agent on blood vessel formation in the eye in an intact mouse.
However, systems to study angiogenesis in the laboratory are limited by the transient nature of angiogenic events and limited accessibility to angiogenic tissues. Sources of endothelial cells currently used in the laboratory include human umbilical vein, and bovine aorta, pulmonary vein, and pulmonary artery (Jarrell et al. J. Vasc. Surg. 1984 1:757–764; Simonescu, N. and Simonescu, M. (eds) Endothelial Cell Biology in Health and Disease. New York: Plenum Press, 1988; Thilo-Korner, D. and Freshmey, R. I. (eds) In the Endothelial Cell—A Pluriopotent Control Cell of the Vessel Wall. Basel:Karger, 1983). A malignant hemangioendothelioma of murine origin is also used for studying endothelial cell biology (Obeso et al. Lab. Invest. 1990 63:259–269). Other endothelial cells, such as those derived from bovine adrenal cortex or retina, rat brain, and mouse aorta, epididymal fat pad, thoracic duct, or liver have been more difficult to maintain in stable long term culture (Gumkowski et al. Blood Vessels 1987 24:11–23; Jaffe, E. A. (ed.) The Biology of Endothelial Cells. The Hague: Martinus Nijhoff, 1983; Kumar et al. Differentiation 1987 36:57–70).